Mouth: Food is taken into the mouth, chewed and mixed with saliva which contains the enzyme, ptyalin.
Oesophagus: The oesophagus is the long tube connecting the mouth with the stomach. Food passes down this tube after it has been swallowed. The food is in the form of a small lump called a bolus, and it is pushed down by the muscular contractions of the wall of the oesophagus; this process is called peristalsis.
Stomach: This acts as a reservoir for food which is held while being mixed with hydrochloric acid, mucous and some enzymes. Food is broken down in the stomach but no absorption takes place.
Ileum or Small Intestine: This is a long tube down which the food is pushed by the action of peristalsis. While it passes along, it is acted on by bile from the gall bladder and enzymes from the pancreas and from the walls of the ileum. The food is finally broken down to glucose, amino acids and glycerol and fatty acids, and these compounds are absorbed through the wall of the ileum into the blood stream of the animal.
Caecum: The caecum is a long, convoluted tube ending in the appendix. It is here that cellulose is broken down by bacterial action and converted into glucose. This is an important organ as the Rabbit lives on raw vegetable matter such as hay, cabbage leaves etc. Without a large caecum, the animal would be unable to utilise this type of food.
Colon or Large Intestine: The main function of this organ is to absorb any water remaining in the waste that is left after the food has been broken down and absorbed. After the water has been absorbed, the waste that remains passes out of the anus in the form of small, round, moist droppings.
Bladder: The bladder stores the liquid waste left after digestion and absorption, and this passes out of the animal in the form of urine.